SecurePro Thumbscrew Click HERE for more information! Our SecurePro GoPro thumbscrew is CNC milled from a single aluminum billet. The end of the bolt has a thru hole that accepts a cotter pin which eliminates the possibility of the thumbscrew coming undone. We’ve also included our Thumbscrew Wrench in this package making it the ultimate security package for GoPro mounts! CNC milled aluminum billet. Stainless steel 5mm X 0.8 bolt. Stainless steel cotter pin. CNC milled thumbscrew wrench included. Weighs just 0.65 oz